This invention relates to a pump chamber assembly for an intravenous pump of the diaphragm-type. More particularly, this invention relates to a pump chamber cassette for an intravenous pump wherein the pump chamber is constructed in a manner with inlet and outlet ports and is retained in a pump in a position so that air bubble entrapment is substantially eliminated.
Pump chambers of the type concerned with in this invention are described in U.S. Pat. No. 4,199,307. In this particular patent, a specific configuration of a cassette is described for use in a peristaltic-type pump. In U.S. Ser. No. 34,826 filed Mar. 30, 1979 by the assignee of this application, an intravenous pump chamber is illustrated for use with a diaphragm-type pump wherein a diaphragm member is positioned on a pump chamber housing in a manner specifically suitable for large scale production. U.S. Pat. No. 4,079,736 illustrates another version of an I.V. pump cassette which is indicated therein by the numeral 17.
In utilizing diaphragm-type pumps with the types of pump chamber cassettes previously described, a problem arises with the entrapment of air in the pump chamber. When this occurs, accuracy is sacrificed in that air can accumulate in the pump chamber and thus an accurate amount of fluid will not be pumped from the chamber.
It is an advantage of the present invention to provide an intravenous pump chamber cassette which will afford accurate delivery of I.V. fluids. Other advantages are a pump chamber cassette which substantially reduces the accumulation of air bubbles therein; an intravenous pump chamber cassette which includes orientation means to assure that the pump chamber is positioned in the pump in a predetermined manner; a pump chamber assembly which is held in the pump in a predetermined position so as to cause any air bubbles to migrate to the outlet passage; a pump chamber cassette which has means in conjunction with the orientation means to activate the pump when it is positioned therein; a pump chamber assembly which is formed as an integral part of an I.V. administration set and is fabricated at low cost.